I'd be more worried about the gas generator you're going to need to power it

Seriously, why do you need 45w X 4 speakers? To cancel out Road noise? Engine noise? Running full tilt, that player is going to draw 15 amps, and I have a feeling that a 50 pound battery isn't going to last more than a couple of hours. Yeah, I know, you're not going to play it THAT loud...

Still, you'd be better off with a flea powered amp and highly efficient speakers. As an example speakers that have a 96 db sensitivity rating draw only half the power of a speaker that's rated at 93db. For every 3db change the power requirements doulble or half, depending upon which way you're going.

Here's a better example. a speaker rated at 89 db (and there's a ton of them out there) will need 4 times more power to put out the same sound as one rated at 95 db. So if you had a 10 watt amp with the 95 db rig you'd need a 40 watt amp to run the 89 db speakers at the same sound level.

More efficent equals less power, less battery and less weight.

That said...It doesn't matter how good your speakers are, they still SUCK half the time

OK, got the radio in its water proof housing, got my two speakers from west marine. Wired it up to a battery charger and at fairly loud volume it was still reading under two amps draw. Not very scientific, need to get an OhM meter on it. But better than it topping out the chargers 10amp max!

Let's see Power=Volts X Current So If we divide 45 watts per channel by 12 volts we get 3.75 amps per speaker at full volume, or for 4 speakers it'd be 3.75 amps X 4 = 15 amps.

Is your player 45 watts per channel or is its total output 45 watts and about 11 watts per channel?? Even at 11 watts you're drawing less current than the calculated .9A per channel (3.6 for 4 channels). If it's 4.5 watts per channel, I'd buy that @.375A per Channel or 1.5 total.

I don't get it. That Ohm's fellow used to be a pretty sharp dude, but he's letting me down here.........Then again it could be me making the error.

these were amp ratings pulling thru a multi meter. Only running two speakers and i'm guessing the 45watts is a very generous peak wattage not RMS. I didin't turn it up to full volume to get a reading in fear of blowing the speakers.

The radio project hit a bit of a snag. I was going to mount the radio on top of the cooler chest. i have a remote now so we would not have to open the water tight box. BUT the smoked lid to the box doesn't let me see the radio numbers in full sun so there is no point in keeping it there. The speaker placement does look nice though. I'll have pictures in another week.

Here's an idea I'm going to use this season. I got an "Otterbox" or EGO Ice" for my Ipod Video. It's completely self contained waterproof clear plastic and is equiped with speakers. It uses AA batteries to power the speakers. I used it on vacation this past fall and the sound was actually pretty good.

I'll put it in a tramp bag and cruise with a playlist I've yet to put together

Does anyone know if you get a lot of "rattling" when marine speakers are installed in the plexiglass cabin doors? Many car trunks suffer from this rattling and it's annoying... just wan't to know if I'll be having to deal with getting around this problem...-Jimbo

Here is a set of waterproof speakers that are rechargable and 300 Watts. If you want to provide a small battery you can get 600 Watts. Should be no problem to power these......Small, compact and powerful.